Sorry, diolma.  I didn't see your comments before posting my last reply.   I have certainly resorted to hiding figures in some scenes and I know that does help, but this scene was actually pretty basic, so there didn't seem to be any internal justification for the poor performance.

The 55% was actually a percentage of the processor .   Admittedly, Poser will take 99%, when it's actually doing anything, but it was using a lot of the processing power, even when not apparently active.